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© copyright 1992, 1996 by Powertec Industrial
Motors
If the MAX SPD is set too high, the motor will stop
increasing in speed before the operator speed pot reaches
its full range (100% clockwise). In this case the CUR-
RENT LIMIT light will come on, though little current is
being used, and the speed will be erratic. Turn the MAX
SPD pot counter-clockwise until the CURRENT LIMIT
light goes out (even if this is below base speed) to attain
speed control, and then set the MAX SPD pot (see the cold
motor note above).
Remember that this Model 2000C and 3000C maxi-
mum speed adjustment is in reality just a calibration to the
input reference of 10VDC. It is not an absolute speed limit.
If more than 10VDC is applied to the reference input, the
motor will go faster (the input circuits clamp the input
reference at +10.6VDC).
DO NOT ATTEMPT TO MAKE A MOTOR RUN AT ANY
SPEED GREATER THAN ITS BASE SPEED UNLESS THE
MOTOR WAS PURCHASED FOR HIGH SPEED OPERATION
FROM THE FACTORY.
5.1.5 RAMP STOP
The RAMP STOP jumper, when installed, main-
tains the control in the enable condition after a stop
command is given (+24VDC is removed from TB2 termi-
nal 5 by the ramp stop button, or from TB2 terminal 4 when
a switch or contact is used). The input speed reference is
clamped to zero.
This will decelerate the motor to zero speed (the
motor will coast to rest if the coast time is greater than the
DECEL time), and, when the motor gets below about 10
RPM, the control shuts off and after that it must be re-
started with a RUN command to TB2 terminal 4.
If the RAMP stop jumper is not installed, a ramp stop
shuts off the control and the motor coasts to a stop.
5.1.6 JOG FUNCTION
POWERTEC Models 2000C and 3000C have a
built-in JOG function which is used to turn the motor, for
short periods of time, without using the RUN function.
The JOG function does not seal in and hold itself on
as does the RUN function. JOG will accelerate the motor
very rapidly when +24VDC is applied to TB2 terminal 13
and then decelerate the motor very rapidly to zero speed
when the voltage at terminal 13 is removed (the +24VDC
should come from a point after the Emergency Stop
button). See Section 4.4 and Table 1 on page 4-7).
Speed is determined, in the analog mode, by the
setting of the on-board JOG potentiometer, which is ad-
justable from zero to about 15% of the MAX SPEED
setting. (Speed in the digital mode is determined by an
external frequency applied while the JOG is active.)
There is no ACCEL or DECEL ramp in the analog
JOG mode. The JOG reference produces the JOG speed
output as a step function, where the acceleration or decel-
eration of the motor is limited only by CURRENT LIMIT.
If a jog function with ACCEL and DECEL is de-
sired, it is better to use a non-latching RUN function for
jog. This may be accomplished by opening up the connec-
tion to the RUN holding terminal TB2 terminal 5 and
applying a RUN command to the RUN terminal at TB2
terminal 4. As long as TB2 terminal 5 is open, the drive will
RUN only as long as contact closure on TB2 terminal 4 is
maintained. When that contact is opened, the control will
ramp stop the motor, if the ramp stop jumper is installed.
Speed in this mode will not come from the JOG pot, but
from the reference input at TB2 terminal 10.
5.1.7 BI-DIRECTIONAL JOG
The capability for jogging in either direction in a
system must be installed. It is not built into the system.
This requires simultaneous application of a directional
signal (+24VDC at TB2 - 14) and a speed signal (from the
JOG pot in ANALOG mode, or a frequency representing
JOG speed in DIGITAL mode).
In ANALOG mode, the direction of the motor in
JOG is determined by the presence or absence of +24VDC
at TB2-14. With the FWD/REV terminal 14 at 0VDC (or
if the terminal is open), forward JOG will result if the JOG
input (TB2 terminal 13) is activated. Activating the JOG
with +24VDC at terminal 14 will result in a reverse JOG.
Speed command in JOG comes from the JOG pot.
Bi-directional JOG may be accomplished in the
same way in the DIGITAL mode, but if the control remains
in the DIGITAL mode during the JOG function, a fre-
quency for the JOG speed must be supplied at TB1- 11,
with respect to TB1-9, which is NOT the drive common.
TB1-10, which is the input for the DIGITAL mode, is also
referenced to terminal 9. Terminals 9, 10 and 11 on TB1
are an isolated circuit. See Figure 16, Section 4.5.2.
RAMP STOP JUMPER TABLE
ANALOG MODE
IN
Upon the RAMP STOP command, the
motor decelerates to zero speed at
the DECEL rate, or coasts to stop
if coast time is longer than DECEL
time, then the control shuts off.
OUT
Control shuts off immediately upon
a RAMP STOP command. The motor
will coast to a stop.
DIGITAL MODE
IN
The input frequency must be
reduced to zero when the RAMP STOP
command is given; the motor coasts
to a stop if the frequency is
reduced faster than the coast time
of the motor and load, then the
control shuts off.
OUT
Control shuts off immediately upon
a RAMP STOP command. The motor
will coast to a stop.
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